This invention relates to block and tackle window balance devices for single and double hung windows and, more particularly, to a block and tackle window balance device that provides an increased range of travel within a window frame.
Hung window assemblies generally include a window frame, a lower window sash, an upper window sash, a pair of window jambs, two sets of jamb pockets, and at least one window balance device for offsetting the weight of a window sash throughout a range of travel within the window frame. Block and tackle window balance devices use a combination of a spring and pulleys located within a channel to balance the weight of the window sash at any position within the jamb pockets.
In some block and tackle window balance devices, the channel containing both the spring and pulleys is attached to the window sash, and a cord, which connects the pulleys together, is attached to a jamb mounting hook that is connected to a side jamb. A disadvantage of this type of device is that the travel distance of the window sash is limited by some of the pulleys located within the rigid channel interfering with the jamb mounting hook that attaches the window balance to the window jamb.
In general, in one aspect, the invention relates to a block and tackle window balance device for use with single and double hung windows that affords increased window opening travel distance. In one embodiment, the block and tackle window balance device includes a channel, a spring with a first end and a second end, a translatable pulley block unit, a fixed pulley block unit, a cord, a top guide, and a bottom guide with a bottom guide roller. The top and bottom guides are connected to opposite ends of the channel. The spring, the translatable pulley block unit, and the fixed pulley block unit are all located within the channel. The first end of the spring and the fixed pulley block unit are fixed at opposite ends of the channel. The second end of the spring is connected to the translatable pulley block unit. The translatable and fixed pulley block units are connected by the cord. The cord is threaded around both the translatable and fixed pulley block units and extends around the bottom guide roller located within the bottom guide.
In another embodiment, the block and tackle window balance device includes a top guide including a top angled portion and a bottom portion. The bottom portion of the top guide is connected to one end of the channel. In still another embodiment, the top angled portion of the top guide is sized to receive a member from a window sash.
In yet another embodiment, the block and tackle window device includes a bottom guide that extends beyond the rigid channel. In still yet another embodiment, the bottom guide of the device further includes a channel to receive a portion of a window sash.
In general, in one aspect, the invention relates to a method of providing increased travel of a window sash slidably mounted in a window frame. The method includes three steps. A first step is to provide a window assembly that includes a window frame with jambs with jamb pockets, an upper window sash, a lower window sash, and at least one block and tackle window balance device having a channel and a bottom roller for dispensing a cord. The channel has a first end and a second end. The bottom roller is mounted proximate to the second end of the channel with a first distance between the first end of the channel and the bottom roller. A second step is to remove the block and tackle window balance device from the window assembly. A final step is to provide and to install an increased travel window balance device. The increased window balance device has a channel with a first end and a second end and a bottom guide roller for dispensing a cord. The bottom guide roller is mounted proximate to the second end of the channel and a second distance is defined as the length between the first end of the channel and the bottom guide roller. The second distance of the increased window balance device is greater than the first distance of the removed block and tackle window balance device.
The foregoing and other objects, aspects, features, and advantages of the invention will become more apparent from the following description and from the claims.